Ah. I see, makes sense.
So I have now three rules (I like rules or recipes):
- Writing only one system should produce a set of components.
- Many system can read various components and react.
- If many system produce the same components they better produce an entity with those components and link them to the entity they did want add those components.
I’m not totally sure if I understand the special case, but I think I understand that when two or more system produce the same component they stumble over each other, so if they produce an entity with that component and problem is solved.